The present invention relates to a quantitative continuous supplying method using the action of ultrasonic vibration and more specifically to a method capable of quantitatively continuous-supplying by the action of ultrasonic vibration small particulate matters having a diameter of 500 xcexcm or larger, which has hitherto been difficult to supply by the action of ultrasonic vibration, by limiting the shape of the resin fine particulate matters to be quantitatively supplied to a definite range; a production method of moldings using the above-described method; and a thermoplastic resin composition used for the above-described method.
A general feeder conveys powders or particulate maters by rotating a screw or a spiral-form rod, and supplied a definite amount of powders or particulate matters by a method of supplying a definite amount thereof by controlling the rotation number or while calculating a part or the whole of the feeder and by detecting the changing amount to reflect it to the rotation number. As a specific form of the feeder, there is a feeder using a ultrasonic wave and such a feed is known as a ultrasonic motor-type powder feeder.
The basic principle and the controlling method of the ultrasonic feeder are described in JP-A-7-33228 (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d), U.S. Pat. No. 5,917,266, DE 19742663, U.S. Pat. Nos. 6,050,393, 5,906,294, and 5,929,552, JP-A-278902, etc. The ultrasonic feeder utilizes the synthetic elliptical motion of the longitudinal vibration and the bending vibration at the tip of the ultrasonic motor and has been developed for carrying out the continuous quantitative supply of a slight amount of particulate matters, mainly metal powders having a diameter of not lager than 500 xcexcm with a high accuracy.
In the case of particulate matters having a diameter of 500 xcexcm or larger, it sometimes happened that safely conveying the particulate matters by only the vibration of ultrasonic wave was difficult. Therefore, it was not practiced to continuously supplying pellets of a colorant or an additive for a synthetic resin, having a diameter of 500 xcexcm or larger, by the ultrasonic feeder.
On the other hand, as a method of adding and compounding a colorant or additive(s) to and with a thermoplastic resin in the case of producing extruded moldings or injection moldings using a screw feed extruder, a master batch has been used in various fields because of the easiness of handling at adding and compounding. The master batch contains one or more kinds of colorant(s) and additive(s) and is kneaded with a resin and the like, which becomes a vehicle, in a body. The using method of the maser batch differs according to the difference in a supplying method thereof.
Such a master batch is generally diluted with resin pallets to be colored or to be added to from 5 to50 times, after mixing by a tumbler, mixer, and the like, the mixture is placed in a hopper, kneaded by a heated extruder screw for molding, and after being unified, is molded.
As other method, there is a method of continuously supplying to a molding machine while measuring the weight or the volume and in the method, the maser batch and a resin are generally conveyed by the rotation of a screw or a spiral rod. In the method, by separating the inlet of the master batch and the inlet for a resin to be treated, the master batch can be supplied without being restricted on the shape of the master batch.
JP-A-11-279282 discloses pellet-form thermoplastic resin composition, which is used for the above-described method, capable of establishing a high dilution ratio by improving the peptizing property and the quantitative supplying property.
On the other hand, JP-A-60-18529 proposes the use of a mixture of a mater batch largely containing a flame retardant or a filler with a coloring master batch and a resin to be colored. However, actually, because the separation of the mater batches occurs, the desired result has not yet been obtained. Accordingly, it has been considered to be difficult to add the mixture in the base color as it is before the final molding step. To solve such a fault, in JP-A-7-216099 it is proposed, about the at least two kinds of pellets constituting the composition, to reduce the specific gravities thereof with a foaming agent, etc., or controlling the apparent specific gravity of each constituent by increasing the specific gravity thereof with an inorganic filler.
Certainly, according to the method, the specific gravity difference of each base color master batch can be controlled below 0.5 g/cm2. However, since by the addition of a foaming agent and an inorganic filler, a cost up and the deterioration of the quality occur, and further since the errors of the addition amounts of the foaming agent and the inorganic filler by calculation from the practical ratio are large, and also the management terms are increased to complicate the steps of the method, it is the actual circumstances that there are many different points for practically using by controlling the additives.
Also, in JP-A-7-102155, it is proposed to establish the weight of a colorant master batch to pellets to be colored to the ratio of from 0.45 to 0.95 for preventing the occurrence of uneven color of the colored moldings caused by the separation of maser batch. However, in the method, it is the actual circumstances that the shape deviation becomes large in the field of requiring the addition of a large amount of an inorganic pigment and it is difficult to keep a uniform mixed state.
Also, JP-A-11-279282 discloses synthetic resin pellets on the assumption that the pellets are used for a quantitative supplying apparatus using a screw-type feeder of background art. However, the disclosed invention relates to coloring pellets for being mixed with rein pellets to be colored having ordinary sizexc2x7shape, and in the invention, the pellet size is finer than an ordinary level, and by forming fine particle sizes of the dimensions in a specific relatively narrow range and making a shape indispensably having a partially flat surface such that the orthogonal projection for a certain direction of the particle shows a regular square or a rectangle, the uniform mixing performance and the quantitative supplying performance of the pellets are improved to effectively prevent the occurrence of uneven coloring, etc., whereby satisfactory effects are obtained. However, the content of the invention disclosed in the above-described patent invention utilizes a screw-type feeder and it is the actual circumstances that the problems described below occurring the use of a screw-type feeder have not been solved.
A feeder for quantitatively supplying a material to a screw-type extruding kneader of background art is generally one wherein a screw and a motor are connected in a body and there is a problem that the structure is larger than a ultrasonic feeder and a power for moving a large apparatus is necessary, and also at cleaning the feeder in the case of changing a material to be conveyed, there is a problem that a labor of dismounting complicated apparatus and cleaning is required, and furthermore, there is also a problem that a long time is required until the material supplying amount at the practical production reaches a desired established value and is stabilized.
On the other hand, a ultrasonic type powder feeder was developed for carrying out the continuous supply of powders having a diameter of not larger than 500 xcexcm with a high accuracy but it was difficult to use the feeder for carrying out a stable continuous supply of particulate matters having a diameter of 500 xcexcm or larger. The 1st reason that the stable continuous supply is difficult for the particulate matters having a diameter of 500 xcexcm or larger is in the point that by increasing the particle sizes, there is a limit in the distance of moving the particulate matters by the vibration only of ultrasonic waves and a continuous flow of particulate matters that the pushed particulate matters move and next particulate matters are brought into contact with the vibrating surface of ultrasonic waves is hard to occur, whereby a continuous supply of the particles with a high accuracy becomes difficult. Also, the 2nd reason that feeding the particulate matters having a diameter of 500 xcexcm or larger is difficult is in the point that when particulate matters become large, the contact areas of the particulate matters with the vibration surface of ultrasonic waves per unit weight become small, whereby it becomes difficult to move the particulate matters by the vibration force only of ultrasonic waves.
Thus, for solving the above-described problems of background art, an object of the present invention is to provide a method of capable of stably and continuously supplying even fine particulate matters having a diameter of 500 xcexcm or larger by utilizing the merits of a small-sized ultrasonic feeder without need of a labor and time for cleaning the feeder at changing the material to be conveyed and also without requiring a long time for attaining the desired established supplying amount, to provide a method of producing moldings used the method, and also to provide synthetic resin fine particulate matters which can be applied to the method.
That is, as the result of various investigations for solving the above-described problems, the present inventors have found that when synthetic resin fine particulate matters are in a certain range, the particulate matters can be stably and continuously supplied by using small-sized ultrasonic feeder without need of a labor and time for cleaning the feeder at changing the material to be conveyed and also without requiring a long time for attaining the desired established supplying amount, and have accomplished the present invention.
That is, for solving the above-described problems,
(I) An aspect of the present invention provides a quantitative extrusion supplying method of continuously supplying synthetic resin fine particulate matters by the action of ultrasonic vibration, wherein the synthetic resin fine particulate matters are columnar or square column-form small pellets, in which when the longitudinal length, the width, and the height thereof on the three-dimensional rectangular coordinate are x, y, and z respectively,
(1) the sum of the longitudinal length, the width, and the height (x+y+z) is in the range of from 0.9 to 4.6 mm, and
(2) each value of x, y, and z is at least 20% of the sum (x+Y+z) of the longitudinal length, the width, and the height (hereinafter, is referred to the 1st invention).
Also, for solving the above-described problems,
(II) other aspect of the invention provides a method of producing extrudsion moldings or injection moldings by supplying a raw material resin to be colored or to be added to an inlet of a screw feed extruder, continuously supplying a particulate colorant master batch or a particulate additive master batch through a quantitative supplying apparatus to the extruder separately from the raw material resin from an inlet separately formed from the inlet for the raw material resin, and melt-kneading the both constituents, wherein
(A) the colorant or the additive is columnar or square column-form small pellets, in which when the longitudinal length, the width, and the height thereof on the three-dimensional rectangular coordinate are x, y, and z respectively,
(A-1) the sum of the longitudinal length, the width, and the height (x+y+z) is in the range of from 0.9 to 4.6 mm, and
(A-2) each value of x, y, and z is at least 20% of the sum (x+Y+z) of the longitudinal length, the width, and the height,
(B) the pellets are pellets of one color colored in a base color or a desired color or of a mixed state of at least two base colors, or are pellets containing at least one additive other than a colorant, and
(C) the quantitative supplying apparatus of the colorant or the additive is an apparatus of quantitatively extruding supplying the synthetic resin fine particulate matters by the action of ultrasonic waves (hereinafter, is referred to the 2nd invention).
Furthermore, for solving the above-described problems,
(III) still other aspect of the invention is to provide a thermoplastic resin composition containing a pellet-form colorant or additive, without carrying out a mixing operation of a resin composition containing a colorant or an additive with a raw material resin to be colored or to be added by a blender or a mixer, which is used in the case of continuously supplying to the upper portion of the screw of a molding machine using a quantitative supplying apparatus of supplying synthetic resin fine particulate matters by the action of ultrasonic vibration, wherein
(A) the pellet-form colorant or additive is columnar or square column-form small pellets, in which when the longitudinal length, the width, and the height thereof on the three-dimensional rectangular coordinate are x, y, and z respectively,
(A-1) the sum of the longitudinal length, the width, and the height (x+y+z) is in the range of from 0.9 to 4.6 mm, and
(A-2) each value of x, y, and z is at least 20% of the sum (x+Y+z) of the longitudinal length, the width, and the height, and
(D) in the pellets, the orthogonal projection from a certain direction shows a square or a rectangle (hereinafter, is referred to as the 3rd invention).
Moreover, for solving the above-described problems,
(IV) another aspect of the invention provides the thermoplastic resin composition of above-described (III) wherein the pellets are;
(E) a material in which when in the two adjacent sides of the regular square or the rectangle becoming the orthogonal projection thereof, a long side is (a) and a short side is (b), the value of (a)/(b) is in the range of from 1 to 1.4, and also
(F) a material in which about optional 10 pellets, when average value of the sum total value of the lengths of the adjacent two sides is (c) and the standard deviation thereof is (d), the value of (d)/(c) does not exceed 0.1 (hereinafter, is referred to as the 4th invention).